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speciation n.
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Speciation PowerPoint Presentation

Speciation

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Speciation

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  1. Speciation • evolution of a new species • occurs when members of similar populations no longer interbreed to produce offspring in a natural environment

  2. In order for their to be speciation, there must be isolation

  3. Geographic isolation - when a physical barrier divides a population • volcano • earthquake (produce islands) • flood

  4. Gene pools will evolve separately • can become different enough to be separate species

  5. Speciation

  6. Reproductive isolation • Populations can no longer produce fertile offspring • genetic material can be so different that reproduction is not possible

  7. Behaviors can also prevent reproduction • mating at different times of the year

  8. Patterns of Evolution

  9. 1) Convergent evolution • distant related organisms evolve similar traits • develop structures for the same function • analogous structures

  10. Convergent evolution

  11. 2)Divergent evolution • pattern where species that were similar to an ancestral species become more distinct • become less alike as they adapt to separate environments • homologous

  12. Divergent Evolution

  13. adaptive radiation - a species adapts into a variety of species to fit many diverse habitats • Finches’ beaks adapted to food sources on Galapagos Islands

  14. Adaptive Radiation

  15. Adaptive Radiation

  16. ADAPTIVE RADIATION –An example of divergent evolution http://www.vanderbilt.edu/AnS/english/Clayton/Galapago_finches.gif http://evolution.berkeley.edu/evolibrary/home.php

  17. Artificial Selection • Breeding organisms for desired traits • Agriculture (plants and livestock) • Dogs and other pets

  18. Artificial Selection

  19. What about Super Cow?